We have been seeing some reports of omnibus users reporting that their quad suddenly starts twitching at a random point in the flight. This actualy is caused when you enable blackbox logging to the SD card and is a bug on betaflight at the moment and seems to affect anything from V3.1.

An example of this is shown in this video (the user is manually disarming the FC mid flight which causes the quad to come tumbling back down to the ground)

Fortunately for now there seems to be an easy fix that all you need to do is disable DMA mode from the CLI:

set sdcard_dma = off

DMA (i dont know what teh acronym stands for, so let me know if you do) but essentially this is used to control bi-directional read/write on the SD card. But for logging you just need to write to it.

You can track the progress of this bug over on the betaflight github page: